Luminaires are electrical devices for creating artificial light by using one or more light engines, e.g. electrical lamps such as fluorescent lamps, halogen lamps, solid state lighting (SSL) elements such as LEDs, and so on. Examples of luminaires include, but are not limited to, large-area office troffers, down lights, and so on. Such luminaires typically comprise a housing delimited by a light exit structure and a cover. In order to provide the luminaires with the desired mechanical strength or rigidity, the cover is typically made of a rigid metal structure shaped, e.g. folded, in a desired shape such as a metal box or the like. An example of such a luminaire is disclosed in US 2012/0262918 A1 which has a cover or receptacle having at least a bottom made of aluminium, copper or stainless steel.
A particular challenge luminaire manufacturers are facing is to reduce the manufacturing cost of such devices. The cost is typically dominated by the cost of the light engine(s) and the cost of the cover. Where the one or more light engines are SSL elements, cost reductions are provided by the on-going development of such light engines, i.e. the maturation of the SSL element industry. However, it is less straightforward to reduce the cost of the cover, as its cost is typically dominated by its manufacturing process, i.e. the efforts involved to shape or mold the cover in its desired shape.